| Numéro |
J. Phys. Colloques
Volume 42, Numéro C6, Décembre 1981
International Conference on Phonon Physics
|
|
|---|---|---|
| Page(s) | C6-587 - C6-589 | |
| DOI | https://doi.org/10.1051/jphyscol:19816171 | |
International Conference on Phonon Physics
J. Phys. Colloques 42 (1981) C6-587-C6-589
DOI: 10.1051/jphyscol:19816171
Institute of Organic and Physical Chemistry, Technical University, 50-370Wroclaw, Poland
J. Phys. Colloques 42 (1981) C6-587-C6-589
DOI: 10.1051/jphyscol:19816171
HARMONIC AND ANHARMONIC REPRESENTATION OF LIBRATIONAL MOTIONS IN MOLECULAR CRYSTALS
B. Kuchta et T. LutyInstitute of Organic and Physical Chemistry, Technical University, 50-370Wroclaw, Poland
Abstract
The orientational crystal potential, represented as a surface in n-dimensional space spanned on librational normal coordinates, has been calculated for α-N2, α-O2 and β-O2 crystals and compared with its harmonic representation. Significant differencies in symmetries of the surfaces show that molecular librations are highly anharmonic and that any proper description of the excitations in molecular crystals has to take into account the full symmetry of an exact orientational crystal potential.